Changelogs are very important to inform the visitors/potential customers about the latest improvements in your theme. While updating an item, you should write the theme changelogs in the ‘Changelog’ field.
Here are the formats to write changelogs in order to getting the outputs with distinguishable labels.
See this example:
<h4>Version 1.0 - 23 JUNE 16</h4>
<li class="new">New Feature</li>
<li class="update">Feature Updated</li>
<li class="fix">Issue Fixed</li>
And here is the changelog output displayed in the theme description page.
So, under the hood, here we've used several classes to display changelog labels like 'New', 'Update' and 'Bug fix'. This will present your updated theme with more details on what's new about the item.